FIG. 1 is an explanatory diagram showing a guide screen employed in a conventional navigation system disclosed in, for example, Japanese Patent Publication No. Hei 2-55796. In the drawing, reference numeral 1 indicates a screen display unit for displaying a guide screen thereon, and reference numeral 2 indicates a road map displayed on the screen display unit 1. Reference numeral 3 indicates the present position of a mobile body equipped with the navigation system, which is displayed so as to be superimposed on the road map 2, reference numeral 4 indicates the direction in which the mobile body is traveling, and reference numeral 5 indicates the locus of movement of the mobile body.
In the conventional navigation system as described above, the state of the mobile body, instructions for the direction to be guided, etc. are displayed by using the road map 2 and superimposing symbols or the like indicative of the route and the present position 3 of the mobile body on the road map 2. Hence a display screen for such guidance is displayed on the screen display unit 1. Thus, the road map 2 is necessary for the display of the guide screen and the display of the road map 2 has been used for all phases such as the setting of geographic points, the display of the present position, the display of a route, etc.
Since the conventional navigation system is constructed as described above, it has a problem in that information that is not necessarily required for actual driving is included and the guiding screen display is apt to become complex. Hence a great load is placed on a user to recognize the displayed contents.
Further, the present navigation system has another problem in that the size of the screen display unit 1 for displaying the guide screen is apt to increase to clearly display the road map 2 and thus it is hard to suitably install the system when the navigation system is placed in the mobile body.
Moreover, the present navigation system has a further problem in that since a system with high resolution is required to clearly display the road map 2 on the screen, the screen display unit 1 is apt to increase in cost, so that the cost of the entire system increases.
The present invention has been made to solve the above-described problems. An object of the present invention is to obtain a navigation system wherein a route is represented by a quantized bearing so as to simplify the entire screen without displaying a road map on the screen, thereby making it possible to reduce the load on the user as regards the recognition of the displayed contents.
Another object of the present invention is to obtain a navigation system wherein the need for the user to frequently observe a display screen is eliminated by guiding a route by voice.
A further object of the present invention is to obtain a navigation system wherein a road map is not displayed on the screen so as to relax restrictions on the size of the screen display unit, and the screen display unit is simplified to improve versatility of its installation place and allow a reduction in the cost of the entire system.
However, an additional problem arises in that since the user cannot utilize a map as a method for recognizing the present position when the road map is not displayed on the screen in this way, it is necessary to additionally provide means for recognizing the present position.
The present invention has been made to simultaneously solve such problems. An object of the present invention is to obtain a navigation system wherein facilities such as famous roads, railway lines, etc. located in the neighborhood of the mobile body are used to represent the present position thereof and are displayed in the form of a position relative to the present position, thereby making it possible to recognize the present position. The position can be given even by voice so as to ease the situation in which a user frequently views the display screen to recognize the present position.